Apparatus for separating suspended particles from gases



Feb. 15, 1949. .1. BURDOCK ET AL 77 APPARATUS FOR SEPARATING SUSPENDEDPARTICLES FROM, GASES Filed May a, 1947 4 Sheets-Sheet 1 I J. L..BURDOCK ET AL 7 APPARATUS FOR SEPARATING SUSPENDED PARTICLES FROM GASES4 Sheets-Sheet 2 Filed May 8, 1947 ,9 Tra v5 y L. BURDOCK ET AL US FORSEPAR Feb. '15, 1949. J, 2,461,677

- APPARAT ATING SUSPENDED PARTICLES FROM'GASES 4 Sheets-Sheet 3 FiledMay 8, 1947 Feb. 15,1949.

Filed May 8, 1947 J. 1.. BURDOCK ET AL 2,461,677

APPARATUS FOR SEPARATING SUSPENDED PARTICLES FROM GASES 4 Sheets-Sheet 4IN V EN TORS Moms-PH L EU/PDdC/K Patented Feb. 15, 1949 APPARATUS FORSEPARATING SUSPENDED PARTICLES FROM GASES Joseph L. Burdock, OldGreenwich, and Philip F. Best, Riverside, Conn, and Charles B. McBride,

Port Chester,

of New York N. Y., assignors Corporation, White Plains, N.

to The Aerotec Y., a corporation Application May 8, 1947, Serial No.746,746

4 Claims.

Our present invention relates to apparatus for separating suspendedparticles in gases. More particularly it relates to apparatus whichcentrifugally separates light finely divided organic ma terials, such asfood or vegetable products, from air or gas in which the materials arecarried.

Certain materials of the above type, as for example dust from alfalfa orgrain, present special difficulties because of the tendency, due totheir extreme lightness, to float in a receiving receptacle or bin andto pass therefrom back into centrifugal separating tubes and to becarried out with the clean air or gas.

Certain of'these materials also have a tendency to collect gradually inparts o-f-the apparatus which must, therefore, be periodically cleanedto insure that there shall be no accumulation of foodstuifs which mightdeteriorate and contaminate the recovered product,

It is also necessary to avoid or prevent any tendency for thesematerials to collect and pack in any part of the apparatus in such amanner as to plug or stop it from efficient operation.

In our present invention we provide a centrifugal separating apparatusin which the parts may be readily separated for cleaning and be easilyassembled and which avoids any tendency for very fine light separatedparticles to collect or accumulate in any part of the apparatus otherthan the dust receiving receptacle, or to float back into the exhaustcleaned air of the centrifugal separator.

Our invention is applicable to. apparatus in which a number ofcentrifugal separators are arranged in parallel into one end of each ofwhich extends an off-take pipe leaving an annular space into which aninlet, or inlets, directs air or gases circularly or helically toseparate the suspended particles centrifugally. The clean air enters theopen ends of the ofi-take pipes while the separated particles aredischarged from the'opposite or lower end into a common bin.

In our present invention rotary circulation of air in the bin is avoidedby so arranging the inlets to successive or adjacent separators as tocause the gases in adjacent separators to rotate alternately in oppositedirections, that .is, clockwise in one separator and counterclockwise inan adjacent separator.

As the gases continue their rotary motion when discharged into the dustcollecting bin these opposedrotations will counteract each other andprevent.;.any general rotational movement in the dust binwhich mightcause the lighter particles of dust to separate and float back into thecentral chamber. When the parts of the respective separatorsand becarried out with the exhaust or cleaned air.

The inlets may be arranged in any number of ways, either by separateducts or by tangential inlets to the respective centrifugal separatortubes. 1

To enable the apparatus to be readily disassembled and assembled weprovide in one embodiment of our invention a bin for receiving andcollecting the separated particles having a separating ledge on whichmay rest a partition plate carrying a number of centrifugal separatingtubes which open at their outlet ends downwardly into the dust receivingbin. This permits the plate and centrifugal tubes to be readily liftedfrom the dust bin so that all parts are accessible for cleaning.

Above the supporting ledge the bin is provided with an inlet, and abovethe inlet is a second partition plate which may rest upon the upperedge, or a suitable supporting ledge of the bin,'so as to form a plenumchamber in the, space between the two plates.

The upper plate carries outlet or exhaust pipes so spaced and positionedthat each projects downwardly into a corresponding centrifugal tube andis provided with vanes spanning the upper part of the respectivecentrifugal tubes so as to form spiral passages. When the upper plate isremoved and separated from the lower plate the off-take pipes and thespiral vanes are freely exposed for cleaning.

A hinged cover having an outlet is mounted on the upper part of the binso as to swing downwardly onto the upper plate and form an off-takecover is swung out of position and the plates are separated and removedall parts of the apparatus are freely accessible.

The various features of our invention areillustrated by way of examplein the accompanying drawings in which Fig. 1 is a vertical section of aseparating apparatus embodying one form of the invention;

Fig. 2 is section similar to that of Fig. 1 showing various elements ofthe apparatus separated for removal and cleaning;

Fig. 3 is a vertical section on a larger scale of a pair of adjacentseparating tubes or elements of the apparatus shown in Figs. 1 and 2;

Fig. 4 is a side View of one of the separating tubes or elements showingthe off-take pipe in separated position; I

Fig. 5 is a development of an edge of a directing vane of the tube ofFig. 4;

-Fig. 6 is a side elevation of another lform oi separating tube that maybe used in our invention;

Fig. 7 is a horizontal section of the tube taken on line 71 of Fig. 6;

Figs. 8- and 9. are diagrammatic views showing the relation of a numberof separating tubes of the type of Figs. 6 and 7 with one and twotangential inlets respectively;

Fig. 10 is a side view of a number of centrifugal separators of a stilldifierent type arranged in accordance with our invention;

Fig. 11 is a plan view partly in section't'aken on the line il-Il ofFig. 10;

Fig. 12 is a plan view of another form of embodiment of our invention;

Figs. 13 and 14 are respectively side and end elevations of theapparatus as shown in Fig. 12.

Referring more particularly to Figs. land 2 the separating apparatuscomprises a collecting bin i5 having a downwardly tapered bottom It toform a collecting hopper and outlet ll for the removal of collectedparticles and having an inlet Hi at one'side near the upper end of thebin. Somewhat below the inlet !8 the bin is provided with an inwardlyprojecting shoulder or ledge l9 to serve as a support for a partitionplate which when supported on the ledge l9 separates the bin into alower dust collectin or depositing chamber, indicated at I6, and aplenum or supply chamber 2!. The supply chamber 2i is closed by a coverplate 22 which rests on the supporting surface or ledge 23 on the upperend of the bin l5; A cover 2Q, preferably hinged to the bin l5 as at 25,closes down on the plate 22 to form an off-take chamber 26 and isprovided with a suitable outlet opening 21.

The partition plate 2!] is provided with suitably spaced openings inwhich may be mounted the upper ends of centrifugal tubes 28, but thelower ends of which open downwardly into the collecting hopper Hi. Thetubes 28 are raised with the plate 2i! when the latter is lifted fromthe ledge l9, as shown in Fig. 2, and as the assembly of plate 28 andtubes 28 is thus removed from the bin l 5 it is freely open forcleaning.

Similarly the plate 22 is provided with spaced openings in which aremounted oiT-take pipes 29 in such position that they are co-axial withtheir respective tubes 28 and form in each of the latter an annulardownwardly open passage 30.

As shown in Fig. 2 the plate 22 is removed before the removal of theplate 29 and accordingly the ofi-take pipes are lifted free of thecentrifugal tubes 28. This exposes all parts of the offtake tubes forinspection and cleaning.

Mounted on each off-take tube 29 are vanes 3! and 32 so'positioned as tofit into and span the upper part of the annual passage 39 in therespective tubes 28 and thus form a downward spiral passage for gasesfrom the plenum chamber 2| into the various tubes 28.

As shown in Figs. 1, 2 and more particularly in Fig. 3', the vanes and32 of one tube are arranged in reverse relation to those of an adjacenttube so that if the gas or air in one tube is rotated clockwise, whenviewed from above or below respectively, the air or gas in the adjacenttube will rotate counterclockwise.

Consequently as the rotating gases leave the lower ends of the tubes 28with a residual rotational movement the rotation of one tube will opposethat of the adjacent tube and counteract it "so as to prevent thesetting up of'a rotational whirl throughout the hopper l 5 'which'wouldtend to lift'the' lighter "particles into the rotatlngair take pipes 294 from which they could rise through a central vortex into the off-takepipes 29.

It will be understood that any number of rows of tubes can be soarranged as indicated in the latter figures (844), and that in=this casethey would be arranged in a checkerboard manner.

The tubes 28 are slightly flared toward their upper or inlet ends asindicated at 33 in Figs. 3 and .eand have a bell shaped upper edge 34which fits 1 onto correspondingly downwardly curved edges 35 of theopenings in the plate 2t. This enables the tubes 28- to be readilyinserted in and removed from the openings in the plate 26. 1

The vanes Stand 32 are mounted on the ofiand are similarly shaped to fitin contact with the flared part 33 of the tubes 28 so as to insure aclose fit when the pipes 29 are pressed downwardly into the upper endsof the tubes 28.

The vanes 31 and 32 may have a variable slope as indicated in Fig, 5,the upper end or edge 36 approachin a vertical direction and the lowerpart 3'. having a relatively smaller angle to the horizontal. Thisenables the air passing down wardly to be given a horizontal rotarydirection without an impact or bai'rling action.

The assembly of tubes in Figs. 1 to 4 enables the tubes to be veryclosely spaced. Where this iii is not essential or desirable the type oftubes shown in Figs. 6 and 7 may be employed. In this case each tubecomprises a cylindrical wall 33 closed at its upper end and closed atits lower end and having one or more tangential inlets 39 and 40 formedby cutting or slitting an opening and bending back the metal to form thefins; 4| and 42. An off-take pipe 43'projects downwardly into the upperend of the cylindrical tube 38 and terminates at an open end somewhatbelow the level of the inlets 39 and 40 and thus forms an annularpassage into which these inlets deliver.

As shown in Fig. 8 tubes 44 having single inlets 45 are so arrangedthat'the direction of rotation of the gases in the tubes is alternatelyreversed in directions at right angles to give a checkerboard effect tothe difierent rotations.

Similarly in Fig. 9 tubes 46 having two inlets 41 and 48 are similarlyarranged. It will be understood 7 that this arrangement is showndiagrammatically but that any suitable structures may be employed, suchas that shown in Patent No. 2,281,610.

This invention is particularly advantageous with a large number ofcylindrical tubular separators closely spaced, but may beemployed toadvantage with other forms of. centrifugal separators delivering into acommon dust receptacle or bin.

As shown in Figs. 10 and 11. for example, a number of centrifugalseparators 49 deliver into bins50, the particular embodiment showingfour separators for each bin. Each separator is provided with an inletduct 5i supplied with particle carrying air from a common supply conduit52, the conduits 52 being arranged as shown in Fig. 11 foralternatereversal of direction of rotation in successive separators.

The cleaned exhaust gases are withdrawn through ofi-take pipes 53 to anexhaust conduit 54. It will be understood that more than four separatorsmay deliver into a single dust collecting hopper.

The apparatus shown in Figs, ,12; 13 and I4 is similar. A number orcentrifugal lseparators 55 and '56 being arranged in rowsaresu'pplledfrom supply conduits-57 58 and--59 through branches- 1. Apparatus forseparating suspended particles from gases which comprises an open endeddust bin having a peripheral inner said open end, a partition plateremovably supported on said ledge, said partition plate having spacedopenings, centrifugal tubes in said openings and extending into andopening into said dust bin, said dust bin having an inlet above saidledge, a closure plate removably supported on the open end of said binhaving, openings co-axial with those of said partition plate andoff-take pipes one for each centrifugal tube mounted in said closureaxially into its respective centrifugal tube to form an annular passagetherein, each off-take pipe having radially extending deflecting vanesto fit into and span the upper part of said annular passage at an angleto the length of said annular passage to impart acirculatory motion togases passing downwardly through said annular passage, and a cover onthe open end of said bin to form a chamber above said closure plate,said cover having an outlet.

2. The apparatus of claimv'l in which the ledge spaced from plate andprojecting upper ends of said centrifugal tubes are flared outwardly tofit said openings in said partition plate.

3. The apparatus of claim 1 in which the 4 vanes of each separator areinclined in an opposite direction to those of adjacent separators.

4. The apparatus of claim 1 in which said closure plate and ofi-taketubes form a unitary structure which may be lifted freely from the openend of said dust bin when said cover is removed and in which saidpartition plate and said centrifugal tubes form a unit which may belifted from said ledge when said closure is removed.

JOSEPH L. BURDOCK. PHILIP F. BEST. CHARLES B. MCBRIDE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Germany Number Date DateApr. 14, 1937 Number

